Cow, one I see eating wild mint (10)
I believe the answer is:
intimidate
'cow' is the definition.
(I've seen this before)
'one i see eating wild mint' is the wordplay.
'one' becomes 'i' (Roman numeral).
'see' becomes 'date' (synonyms).
'eating' means one lot of letters goes inside another.
'wild' is an anagram indicator.
'i'+'i'+'date'='iidate'
'mint' anagrammed gives 'ntim'.
'iidate' placed around 'ntim' is 'INTIMIDATE'.
(Other definitions for intimidate that I've seen before include "Scare" , "Bully" , "Frighten" , "Strike fear into" , "Cow" .)